河南农业科学 ›› 2022, Vol. 51 ›› Issue (3): 95-103.DOI: 10.15933/j.cnki.1004-3268.2022.03.011

• 植物保护 • 上一篇    下一篇

拟轮枝镰孢二氢乳清酸氧化酶对伏马毒素合成的影响

李绍宽,刘静,赵楠,庞民好,唐博文,赵斌,刘颖超   

  1. (河北农业大学植物保护学院,河北 保定 071001)
  • 收稿日期:2021-12-06 出版日期:2022-03-15 发布日期:2022-05-23
  • 通讯作者: 赵斌(1983-),男,河北保定人,副教授,博士,主要从事药物新靶标发掘研究。E-mail:binzhao@nankai.edu.cn 刘颖超(1968-),女,河北保定人,教授,博士,主要从事玉米穗腐病相关研究。E-mail:liuyingchao@hebau.edu.cn
  • 作者简介:李绍宽(1994-),男,河北邢台人,在读硕士研究生,研究方向:农药学。E-mail:846158982@qq.com
  • 基金资助:
    河北省自然科学基金面上项目(C2021204137)

Effect of Fusarium verticillioides Dihydroorotate Oxidase on the Production of Fumonisins

LI Shaokuan,LIU Jing,ZHAO Nan,PANG Minhao,TANG Bowen,ZHAO Bin,LIU Yingchao   

  1. (College of Plant Protection,Agricultural University of Hebei,Baoding 071001,China)
  • Received:2021-12-06 Published:2022-03-15 Online:2022-05-23

摘要: 拟轮枝镰孢(Fusarium verticillioides)是玉米穗腐病的主要病原菌之一,其产生的伏马毒素是一种有毒次级代谢产物,严重降低玉米品质,威胁食品安全。DHOD基因编码二氢乳清酸氧化酶(DHOD),主要通过参与生命体中的嘧啶合成途径来影响机体的DNA、RNA合成,进而调控次生物质代谢等过程。为明确DHOD基因在拟轮枝镰孢伏马毒素生物合成中的作用,首先分析拟轮枝镰孢DHOD的系统发育关系,然后通过同源重组法创制拟轮枝镰孢DHOD基因敲除突变体,采用高效液相色谱法(HPLC)检测拟轮枝镰孢野生型与DHOD基因敲除突变体伏马毒素产生量的差异,并利用RT-qPCR技术分析DHOD基因及伏马毒素合成相关基因的表达量。系统发育分析及序列同源比对结果表明,DHOD基因在镰孢菌中较保守;PCR和RT-qPCR分析表明,采用同源重组法获得了拟轮枝镰孢DHOD 基因敲除突变体;HPLC分析显示,DHOD基因敲除突变体的毒素产量较野生型显著下降88.32%~93.56%;RT-qPCR检测结果表明,拟轮枝镰孢DHOD基因敲除突变体中fum1、fum6、fum8 和fum13基因表达量较野生型均显著下降。综上所述,拟轮枝镰孢中DHOD基因表达量与伏马毒素的产量呈正相关。

关键词: 拟轮枝镰孢, 二氢乳清酸氧化酶, 伏马毒素, 同源重组, 基因表达, 玉米穗腐病

Abstract: Fusarium verticillioides is one of the main pathogenic fungi that cause maize ear rot.Fumonisins(FBs)are a group of carcinogenic mycotoxins,produced as secondary metabolites by F.verticillioides,which severely reduce corn quality and then pose a threat to food security.DHOD gene encodes dihydroorotate oxidase,which is involved in the pyrimidine synthesis pathway and affects DNA and RNA synthesis in bio⁃orgamisms,thereby regulating the metabolism of secondary substances.Nevertheless,the mechanism underlying the regulation of DHOD gene on secondary metabolites remains unclear.This research aims to investigate the role of DHOD gene in the biosynthesis of fumonisins in F.verticillioides.Firstly,we analyzed the phylogenetic relationship of dihydroorotate oxidase across species,and then created DHOD-knockout mutants of F.verticillioides by homologous recombination. Secondly,we used HPLC(high performance liquid chromatography)to detect the difference in fumonisin production between the wild type and the DHOD-knockout mutants of F. verticillioides.Thirdly,by using RT⁃qPCR,we analyzed the expression levels of DHOD gene and associated genes of fumonisins synthesis in the wild type and knockout mutants.The sequence analysis results showed that the DHOD gene was conserved in Fusarium spp.,and we obtained the DHOD⁃knockout mutants of F. verticillioides using homologous recombination.Compared to the wild type,a significant reduction(88.32%—93.56%)in the fumonisin production was found in the DHOD⁃knockout mutants. Compared with the wild type,the expression levels of fum1,fum6,fum8 and fum13 were significantly reduced in the DHOD knockout mutants. In summary,the expression level of DHOD gene has a positive correlation with the fumonisins production.

Key words: Fusarium verticillioides, Dihydroorotate oxidase, Fumonisins, Homologous recombination, Gene expression, Maize ear rot

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